In next few years large sky surveys will be underway with the aim of
identifying and characterizing galaxy clusters over large portion of
the sky. The astronomical community will deal with tens thousands of
clusters observed in optical (e.g., with DES survey), millimetric
(e.g., with South Pole Telescope survey) or X-ray (e.g., with e-Rosita
mission). With this ambitious and promising expectation in mind, now
it is the right time to investigate the systematics that could affect
the analysis of real data and provide a concrete framework for the
statistical studies we will performed. To address questions both of
cosmology and the smaller-scale astrophysics, we are deciphering the
various connections among observable cluster properties (SZ decrement,
X-ray luminosity and temperature), the intrinsic quantities
(temperature spectroscopic-like and concentration), and the underlying
mass distribution. I will present some results based on a sample of
10000 simulated clusters plus one bullet-like cluster. I will explore
also how X-ray mass estimates agree/disagree with lensing ones.